Methodology — How we calculate California take-home pay
This page documents every rate, bracket, deduction, and assumption used by the calculators on this site, for tax year 2026. If a number on a calculator surprises you, this page is where you verify it.
Tax year
All figures default to tax year 2026. At the time of writing, the IRS had not yet published its full 2026 Rev. Proc. inflation-adjustment release, and the California Franchise Tax Board had not yet issued its final 2026 schedules. We project 2026 figures by applying each agency's standard methodology — IRS chained-CPI based adjustments and California\'s annual cost-of-living adjustment — to the latest officially published brackets.
When the official 2026 numbers are released, we replace projected values with official values. The calculation engine's structure does not change.
Federal income tax (2026 projected)
Brackets
Single:
| Up to | Marginal rate |
|---|---|
| $12,150 | 10% |
| $49,300 | 12% |
| $105,200 | 22% |
| $200,950 | 24% |
| $255,250 | 32% |
| $638,000 | 35% |
| Above | 37% |
Married filing jointly: brackets are roughly 2× single. Head of household: between single and married.
Standard deductions
- Single: $16,100
- Married filing jointly: $32,200
- Head of household: $24,150
The calculator subtracts the standard deduction from wages before applying the brackets. We do not model itemized deductions — for users with mortgage interest, large state taxes (SALT-capped), or significant charitable giving, real federal tax may be lower than the calculator estimates.
California state income tax (2026 projected)
Brackets (single)
| Up to | Marginal rate |
|---|---|
| $11,150 | 1% |
| $26,430 | 2% |
| $41,730 | 4% |
| $57,920 | 6% |
| $73,250 | 8% |
| $374,150 | 9.3% |
| $449,000 | 10.3% |
| $748,400 | 11.3% |
| Above | 12.3% |
Married brackets are doubled. Head of household uses its own published schedule.
Mental Health Services Tax
California adds a 1% surcharge to taxable income above $1,000,000, regardless of filing status. The calculator applies this automatically.
Standard deduction
- Single: $5,650
- Married filing jointly: $11,300
- Head of household: $11,300
Federal payroll taxes (FICA)
- Social Security: 6.2% on wages up to the 2026 wage base of approximately $181,000.
- Medicare: 1.45% on every dollar of wages.
- Additional Medicare: 0.9% on wages above $200,000 (single / head of household) or $250,000 (married filing jointly).
Employers withhold 6.2% Social Security and 1.45% Medicare from your paycheck. Employers separately pay the matching 6.2% and 1.45% to the IRS — that does not affect your take-home but does affect your total cost to your employer.
California State Disability Insurance (SDI)
- Rate: 1.2% (projected; actual EDD rate may vary slightly each year)
- Wage cap: none as of 2024 — applies to every dollar of wages.
- Funds: short-term disability + Paid Family Leave.
Bonus / supplemental wage withholding
- Federal: 22% flat on bonuses up to $1,000,000 per year. 37% on portions above $1M.
- California: 10.23% flat on bonuses and stock options. 6.6% on other supplemental wages.
- Additional Medicare and SDI continue to apply normally.
Self-employment / 1099 calculations
- Net SE income = gross 1099 income − Schedule C business expenses.
- SE tax base = net SE × 0.9235.
- Social Security portion: 12.4% of SE base, up to the wage base.
- Medicare portion: 2.9% of SE base, plus 0.9% above the Additional Medicare threshold.
- Half of SE tax is deductible from federal AGI (above-the-line).
- Federal QBI: 20% deduction on qualified business income, applied federally only.
- California does not conform with QBI — full net SE income is taxed at California brackets.
What the calculator does NOT model
- Earned Income Tax Credit (federal or California).
- Federal Child Tax Credit, Child & Dependent Care Credit.
- California Young Child Tax Credit.
- Itemized deductions (mortgage interest, SALT-capped state taxes, charitable contributions).
- Health Savings Account (HSA) contributions for California state tax (federal HSA tax savings only — California doesn\'t conform).
- Wage garnishments, child support, and other court-ordered withholdings.
- Stock options / ISO AMT exposure.
- Multi-state apportionment for residents who earned income outside California.
- Local property taxes (no California city imposes wage taxes).
Pre-tax 401(k) and Section 125 health
Pre-tax 401(k) contributions reduce your federal AND California taxable wages, but do NOT reduce FICA wages. Section 125 cafeteria-plan health-insurance premiums reduce your federal, California, AND FICA wages. The calculator handles each correctly.
Reproducibility
The full calculation engine is implemented in TypeScript and is deterministic — given the same inputs, you will always get the same outputs. Source rates and brackets live in a single file (lib/taxes.ts) so they\'re easy to audit and update.
Disclaimer
The calculators on CA Paycheck Calculator provide estimates only. They are not tax, legal, or financial advice. Use them to plan and compare; rely on a CPA, enrolled agent, or tax-prep software for actual filings.